Class LayerBStreamedEXTDTAReaderInputStream

java.lang.Object

java.io.InputStream

org.apache.derby.impl.drda.EXTDTAReaderInputStream

org.apache.derby.impl.drda.LayerBStreamedEXTDTAReaderInputStream

All Implemented Interfaces:

Closeable, AutoCloseable

final class LayerBStreamedEXTDTAReaderInputStream
extends EXTDTAReaderInputStream

Implementation of InputStream which get EXTDTA from the DDMReader. This class can be used to stream LOBs from Network client to the Network server. Furthermore, this class is used when layer B streaming is carried out and expects corresponding DDMReader start layer B streaming when the object of this class is instantiated.

Field Summary

Fields

Modifier and Type	Field	Description
private ByteArrayInputStream	currentBuffer	Current data buffer
private final DDMReader	reader	DDMReader.

Fields inherited from class EXTDTAReaderInputStream

isLayerBStream, readStatusByte

Constructor Summary

Constructors

Constructor	Description
LayerBStreamedEXTDTAReaderInputStream(DDMReader reader, boolean readStatusByte)	Constructor

Method Summary

Modifier and Type	Method	Description
final int	available()	Returns the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream.
protected void	onClientSideStreamingError()	Performs necessary clean up when an error is signalled by the client.
final int	read()	Reads the next byte of data from the input stream.
final int	read(byte[] b, int off, int len)	Reads up to len bytes of data from the input stream into an array of bytes.

Methods inherited from class EXTDTAReaderInputStream

checkStatus, getStatus, isLayerBStream, isStatusSet, setSuppressException, throwEXTDTATransferException

Methods inherited from class InputStream

close, mark, markSupported, nullInputStream, read, readAllBytes, readNBytes, readNBytes, reset, skip, skipNBytes, transferTo

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

reader

private final DDMReader reader

DDMReader. Used to get more data.

currentBuffer

private ByteArrayInputStream currentBuffer

Current data buffer

Constructor Details

LayerBStreamedEXTDTAReaderInputStream

LayerBStreamedEXTDTAReaderInputStream(DDMReader reader,
 boolean readStatusByte)
                               throws DRDAProtocolException

Constructor

Parameters:

reader - The reader to get data from

readStatusByte - whether or not to read the trailing Derby-specific EXTDTA stream status byte

Throws:

DRDAProtocolException - if thrown while initializing current buffer.

Method Details

read

public final int read()
               throws IOException

Reads the next byte of data from the input stream.

This subclass of InputStream implements this method by reading the next byte from the current buffer. If there is more data, it will be requested a new buffer from the DDMReader.

Specified by:

read in class InputStream

Returns:

the next byte of data, or -1 if the end of the stream is reached.

Throws:

IOException - if an I/O error occurs.

See Also:

• InputStream.read()

read

public final int read(byte[] b,
 int off,
 int len)
               throws IOException

Reads up to len bytes of data from the input stream into an array of bytes. An attempt is made to read as many as len bytes, but a smaller number may be read, possibly zero. The number of bytes actually read is returned as an integer. This subclass implements this method by calling this method on the current buffer, which is an instance of ByteArrayInputStream. If the current buffer does not have any data, it will be requested a new buffer from the DDMReader.

Overrides:

read in class InputStream

Parameters:

b - the buffer into which the data is read.

off - the start offset in array b at which the data is written.

len - the maximum number of bytes to read.

Returns:

the total number of bytes read into the buffer, or -1 if there is no more data because the end of the stream has been reached.

Throws:

IOException - if an I/O error occurs.

NullPointerException - if b is null.

See Also:

• InputStream.read(byte[], int, int)

available

public final int available()

Returns the number of bytes that can be read (or skipped over) from this input stream without blocking by the next caller of a method for this input stream.

This subclass implements this method by calling available on the current buffer, which is a ByteInputStreamReader.

Overrides:

available in class InputStream

Returns:

the number of bytes that can be read from this input stream without blocking.

onClientSideStreamingError

protected void onClientSideStreamingError()

Description copied from class: EXTDTAReaderInputStream

Performs necessary clean up when an error is signalled by the client.

Specified by:

onClientSideStreamingError in class EXTDTAReaderInputStream